DLL3 might become a predictive immunohistochemical marker in small cell carcinoma of the lung (SCLC). We investigated the influence of pre-analytical handling of samples on the performance of DLL3 immunohistochemistry (IHC) using DLL3 SP347 ready to use assay (Ventana). DLL3 positive cell lines were subjected to different experimental conditions mimicking the pre-analytical variation in daily clinical practice. Formalin fixation of 24 h led to the most optimal results of DLL3 IHC. Longstanding fixation in Cytolyt, methanol-based fixative for cytology samples, but also decalcification using a mix of formic- and hydrochloracid resulted in decreased DLL3 staining. Postponed staining of blanc slides for 3 months also decreased DLL3 IHC. Postponed fixation of the SCLC cell lines did not influence the performance of DLL3 IHC, although this might be different in the tissues than in the cell lines. In conclusion, different pre-analytical variables decrease the performance of DLL3 IHC. These findings are essential for implementing novel predictive immunohistochemical biomarkers in daily pathology practice.

DLL3 可能成为肺小细胞癌 (SCLC) 的预测性免疫组织化学标志物。我们使用 DLL3 SP347 即用型检测 (Ventana) 研究了样品的分析前处理对 DLL3 免疫组织化学 (IHC) 性能的影响。DLL3 阳性细胞系在不同的实验条件下模拟日常临床实践中的分析前变化。24 小时的福尔马林固定导致 DLL3 IHC 的最佳结果。在 Cytolyt 中长期固定，用于细胞学样品的甲醇固定剂，以及使用甲酸和盐酸的混合物脱钙导致 DLL3 染色减少。将空白载玻片的染色推迟 3 个月也会降低 DLL3 IHC。SCLC 细胞系的延迟固定不影响 DLL3 IHC 的性能，尽管这在组织中可能与在细胞系中不同。总之，不同的预分析变量会降低 DLL3 IHC 的性能。这些发现对于在日常病理实践中实施新型预测性免疫组织化学生物标志物至关重要。